A listing of prior patents, known to the inventor and which may be relevant to the invention, is presented below:
Patent No. Patentee(s) Issue Date 4,218,660 Carver 08/19/80 4,445,095 Carver 04/24/84 4,484,150 Carver 11/20/84 4,517,528 Tanaka, et al 05/14/85 4,586,002 Carver 04/29/86 4,594,561 Grodinsky, et al 06/10/86 4,769,615 Liberman 09/06/88 4,808,946 Carver 02/28/89 5,164,991 Johnson, et al 11/17/92
These patents generally are directed to audio amplifiers with transformer couplings, a completely different approach than that of the present invention which places an appropriate "choke" coil in parallel with the A/C power line, that is, across the A/C's "hot" and "common" or "neutral" lines.
The present invention is directed in general to usage in connection with A/C operated, electric or electronic equipment, preferably, for example, audio power amplifiers and preamplifiers, televisions, computers, computer peripherals, and other such electronic component equipment or other electrical equipment or devices, for example, electrical motors, air conditioners and other major and minor appliances, but the principles of the invention are even more broadly applicable.
It is noted that power amplifiers (and other high transient demand loads) and preamplifiers when providing an output signal to either the speaker (in the case of a power amplifier) or power amplifier (in the case of the preamplifier) tend to produce an undesirable, much smaller mirror image of the signal they are processing that modulates the A/C line source.
As an effective cure to this problem the parallel choke approach of the invention, due to the fact that it must be magnetically charged by electricity [either from the A/C line or back electromotive force (emf) from it's load] tends to have a reversing effect on this signal, preventing, eliminating or at least substantially reducing it's presence on the A/C line, thereby providing a greatly enhanced A/C power line signal for the load. Without the choke of the present invention, the otherwise untreated signals are able to modulate the A/C line, as it is resistive (basically a wire going from the utility services transformer to the wall outlet that the load(s) is plugged in to).
Up to now, with very few exceptions, virtually all line conditioners have been a major compromise when used in a line enhancement mode. They will in most cases remove small amounts of line noise generated on a given line by such things as motor starting, small transient disturbances and rarely radio frequency (RF) interference imposed on the line. They do this typically by placing small capacitors and air core or ferrite core chokes in series with the line, along with, for example, a metal oxide varistor (for surge suppression). This provides a low cost (high profit) solution to a very small problem.
In the last few years, research has shown that line borne interference is not the major cause of problems in, for example, audio systems. Further research has shown this to be true of other types of applications as well. It has been found that the equivalent series resistance (ESR) of the line is as critical as it would be in capacitive applications. This ESR is greatly aggravated by the majority of line conditioners, as they place resistive elements in series with the source and the load (the wall outlet and the amplifier). As such, when an amplifier hook-up attempts to produce an audio signal, it must discharge the capacitors contained in its power supply into the speakers. This audio signal is then used to modulate the speakers.
But, if one considers basic physics--for every action, there is an equal and opposite reaction. In the case of an amplifier, the opposite reaction is the modulation of the power supply. No matter how large the power supply is, this modulation is unavoidable. In other words, part of the audio signal is imposed upon the line feeding the amplifier. This signal is then imposed upon other pieces of equipment in the system as well. Isolation transformers cannot stop this type of modulation, as they generally are barely large enough to keep up with the load they are supplying.
Now taking this analysis a few steps further, one should consider the amplifier as a large electric motor. When it tries to start, it produces a significant inverse transient on the line. As it spins up, this load lessens and the line then regains its amplitude. In the case of an electric motor, full rotor speed is (crudely put) the same as an amplifier idling, waiting for a signal. As the load engages the motor, it tends to become a greater load to the line and demands more current. As the audio signal is amplified by an amplifier, its power transformer becomes more of a load, and, therefore, places more of a load on the line.
To make matters worse, while the amplifier is struggling to deal with a resistive line and the further added resistance of any kind of line conditioner placed between it and the A/C receptacle, it is being subjected to all of the other components'noises as well. To give an example of this, consider that a CD player is infusing various kinds of high frequency noise generated by its internal clock, as well as its processing circuitry. A VCR is as guilty as the CD player, as it probably uses a switch mode power supply and plenty of digital processing as well. If one is using a surround sound receiver and a television, the amount of noise is compounded in a source-by-source fashion.
It should be kept in mind that a prior art line conditioner does little or nothing to correct this kind of problem, and, as stated earlier, usually adds to the problem.
The present invention does much in the way of removing the effects of these problems. The exemplary embodiment herein actually provides a transient power supply when the need arises, as well as a blocking effect to the problems that are caused by the operation of electrical devices. It should be understood that, unlike power conditioning units and any transformer coil(s) used therein, the coil used in the present invention is not in series with the A/C line but rather in parallel across the line.
Once one or multiple "choke coil" units is cascaded or "piggy-backed" or otherwise installed, the exemplary embodiment of the present invention effectively removes much of the problems caused by the ESR in the line and quenches much of the noise produced by the rest of the equipment as well. Bass becomes much clearer, imaging is improved, the color becoming richer and more life-like. In apartment buildings where electrical loading is a serious problem, as well as older houses that have marginal power connections, the exemplary embodiment of the present invention will have an even more dramatic effect.
With respect to computers and their peripherals, particularly a high usage piece such as a laser printer that tends to produce problems when the fuser comes on or such as a copy machine that does essentially the same thing, the exemplary embodiment of the present invention make a great difference.
It should be understood that, although the foregoing analysis is directed primarily to audio equipment and the like, as an exemplary application, the benefits are similar in many other electrical/electronic applications.